Cut-off die set

ABSTRACT

A ram-driven cut-off die set of the double-cut type in which sections of tubing are successively severed from a continuous length of tubing by a notching cut followed by a severing cut wherein improved means are provided for mounting and guiding the notching blade in its notching movement. The improved mounting means comprises an upper shaft positioned over the tube path and extending from one side to the other side of the path, a lower guide shaft positioned totally on the one side of the tube path, and a cross slide having a relatively long upper portion slidably journalled on the upper shaft and a relatively short lower portion journalled on the lower guide shaft to maximize the magnitude of the journalling support provided to the notching blade as it makes its reciprocal movement across the tube path to accomplish the notching cut.

This is a continuation of co-pending application Ser. No. 844,568, filedon Mar. 27, 1986, now abandoned.

FIELD OF THE INVENTION

This invention relates to tube cutting apparatus of the type used tocontinuously lengths of tubing from tubing or other elongated stockcontinuously emanating from a mill in the which the apparatus includes acut-off die set operated by a ram and wherein the die set is caused tobe clamped to the tubing during the severing operation and wherein thesevering operation is carried out by a vertically reciprocating cut-offblade. More particularly, the present invention is drawn to animprovement in the notching mechanism which is used in conjunction withthe cut-off die set to notch the upper periphery of the tubing justprior to severing the main cut-off blade.

BACKGROUND OF THE INVENTION

In cut-off die sets of the double cut or pre-notching type, a notchingblade is reciprocated across the upper periphery of the tubing after thetubing is clamped within the die set clamping jaws and just prior todescent of the main cut-off blade or guillotine. The pre-notchingeliminates the cusping or dimpling of the tubing to a large extent tothe point that subsequent reshaping of the ends of the severed length oftubing is not normally required. Whereas this general arrangement of apre-notching cut followed by a final severing operatiton is generallysatisfactory in producing tubing which does not require any subsequentreshaping, it is imperatiive that the notching blade be mounted in sucha way that its reciprocating notching movement is precise and firmlysupported throughout the movement of the blade.

SUMMARY OF THE INVENTION

The present invention is directed to the provision of an improvedmounting means for the notching blade of a cut-off die set of the doublecut of pre-notching type.

According to the invention, an upper guide shaft is positioned over thetubing path and extends from a location on one side of the path to alocation on the other side of the path; a lower guide shaft ispositioned beneath and parallel to the upper guide shaft and totally onone side of the tubing path; a cross slide is mounted for reciprocalsliding movement on the guide shafts; and means are provided to mountthe notching blade on the cross slide for reciprocal sliding movementwith the cross slide across the tube path to accomplish the notchingoperation. This arrangement maximizes the journalling support providedto the notching blade and provides a firm, positive, controlled movementof the notching blade throughout its movement relative to the tubing.

According to a further feature of the invention, the cross slideincludes an upper portion defining a relatively long journal surfaceslidably engaging the upper guide shaft and a lower portion defining arelatively short journal surface slidably engaging the lower guideshaft. In the disclosed embodiment of the invention, the journal meansare provided by through-bores extending respectively through the upperand lower portions of the cross slide so that the cross slide, andthereby the notching blade, is firmly and positively supported andjournalled throughout its reciprocal movement.

According to a further feature of the invention, the cut-off die setincludes a lower platen underlying the tube path; a first support memberupstands from the lower platen at the one side of the tube path andrigidly supports one end of each of the guide shafts; a second supportmember upstands from the lower platen at the other side of the tube pathand rigidly supports the other or remote end of the upper guide shaft;and a third support member upstands from the lower platen between thefirst support and the path and rigidly supports the other end of thelower guide shaft. This arrangement provides a simple and compact mannerof rigidly and effectively supporting the guide shafts and thereby thecross slide without interfering with the movement of the tubing alongits path or with the clamping or cutting operation of the die set.

According to a further feature of the invention, the cut-off die setfurther includes an upper platen assembly including an upper platenoverlying the tube path and a plurality of guide rods extendingdownwardly from the upper platen and guiding the upper platen forreciprocal vertical movement relative to the lower platen; the tubesevering blade extends downwardly from the upper platen over the tubepath; and the support member supporting the remote end of the upperguide shaft comprises a tubular member upstanding from the lower platenand telescopically receiving one of the guide rods on the upper platen.This arrangement combines the cross slide guide structure and the upperplaten guide structure in a single structure and .pa contributes to thesimple and compact arrangement of the invention cut-off die set.

According to a further feature of the invention, the cut-off die setfurther includes a cam member extending downwardly from the upper platenand a cam follower secured to the cross slide and guiding on the cammember to horizontally reciprocate the cross slide on the guide shaft inresponse to vertical reciprocal movement of the upper platen relative tothe lower platen. This arrangement provides a positive and simple meansof driving the cross slide back and forth on the guide shafts andfurther contributes to the compact and effective operation of theinvention cut-off die set.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an end elevational view of a cut-off die set according to theinvention;

FIG. 2 is a top view of the invention cut-off die set with portionsremoved for clarity of illustration;

FIG. 3 is a cross-sectional view taken on line 3--3 of FIG. 2; and

FIG. 4 is an exploded fragmentary view of the mounting means for thenotching blade of the invention cut-off die set.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The invention cut-off die set 10 is adapted to be employed in a tubecutting apparatus and is slidably movable along a set of rails 11extending from the tube-forming mill. The tube cutting apparatusnormally includes a swinging or reciprocating ram mechanism which servesto operate the cut-off die set 10. In die sets of the general type withwhich the present invention is concerned, the cut-off die set ispositioned to receive the tubing as it emanates from the processingfabrication mill and the ram mechanism operates to cause the clampingjaws within the die set to be operated to clamp the die set to therapidly moving tubing. The die set, clamped to the moving tube, movestogether with the tube along the rail set extending from the mill. Theram mechanism then causes the notching blade to make a notching cut inthe upper periphery of the tubing whereafter the main cut-off blade islowered to sever a length from the moving tube. Following the finalsevering cut, the ram mechanism, then operating in a reverse manner,first causes retraction of the main cut-off blade and the notching bladeand then unclamping of the die set from the tube section as the cut-offdie set approaches the end of its travel on the rail set. The cut-offdie set is then returned to its initial position on the rail setpreparatory to initiation of a new cut-off cycle.

Cut-off die set 10 includes an upper platen or shoe 12 and a lowerplaten or shoe 14.

Upper platen 12 overlies the tube path 16 and includes three guide rods,18, 20 and 22 extending downwardly from spaced locations on theunderside of platen 12. Guide rod 18 is positioned on the lefthand ornear side of tube path 16 and guide rods 20 and 22 are positioned at thefront and rear of the cut-off die set respectively on the righthand orremote side of tube path 16. A die jaw cam 24 extends downwardly fromupper platen 12 generally between guide rods 20 and 22 and a cam guide26 extends downwardly from upper platen 12 adjacent the rear edgethereof and on the near or lefthand side of tube path 16.

A plurality of guide sleeves or bushings 28, 30 and 32 upstand fromlower platen 14 and respectively telescopically receive the lower endsof guide rods 18, 20 and 22 so as to guide upper platen 12 in itsreciprocal vertical movement relative to lower platen 14 during the tubesevering operation.

The tubing 34 emanating from the tube forming mill is caused to beclamped to the die set 10 by means of a pair of die jaws 36 and 38 eachhaving a complimentary inner radius contour 40 and 42, respectively,complimentary to the tube contour when the clamping jaws 20 and 22 arecaused to advance toward each other so as to engage tube 34. Thereciprocal clamping and disengaging movement of die jaws 36 and 38 isproduced by sliding movement of an upper die jaw holder 44 and a lowerdie jaw holder 46 slidable on each other. The die clamping jaws 36 and38 are adapted to be reciprocated towards and away from each other insynchronisms with the vertical movement of the upper platen relative tothe lower platen by coaction of die jaw cam 24 passing between a pair ofclamping rollers 48 and 50 carried respectively by the upper die jawholder 44 and lower die jaw holder 46. The manner in which the cam 24coacts with the rollers 48 and 50 to move the die jaws 36 and 38 intoand out of clamping engagement with tube 34 will not be furtherdescribed since this mechanism is known and is not part of the presentinvention. Further details of a mechanism of this type may be found inU.S. Pat. Nos. 4,108,029 and 4,294,147, both assigned to the assignee ofthe subject application.

A main cut-off blade or guillotine 52 is mounted in a blade holderassembly 54 which in turn is secured to the underside and extendsdownwardly from upper platen 12. Die jaws 36 and 38 are slottedtransversely at 55 relative to the tube axis to provide a clearancespace through which the blade 52 will pass upon the ram operatingmechanism reciprocating the upper platen 12 downwardly sufficiently topass through the plane of the tube.

A notching mechanism seen generally at 56 operates to provide a notchingcut in the upper periphery of the tube prior to the downward severingmovement of the guillotine 52 so as to preclude the necessity of furtherworking of the severed tube section following the severing operation.The present invention relates primarily to the improved notchingmechanism 56. Notching mechanism 56 includes a support bracket 58, asupport bracket 60, a support bracket 62, an upper guide shaft 64, alower guide shaft 66, a cross slide 68, and a notching or scarfing bladeassembly 70.

Support bracket 58 is L-shaped in cross section and upstands rigidlyfrom lower platen 14 at the nearside of tube path 16 adjacent thelefthand edge 14a of the lower platen 14.

Support bracket 60 is positioned on the upper end of bushing 32 andincludes a forwardly extending journal portion 60a.

Bracket 62 upstands rigidly from lower platen 14 at a location betweenbracket 58 and tube path 16.

Upper guide shaft 64 is secured at its near or lefthand end in supportbracket 58 and at its remote or righthand end in journal portion 60a ofsupport bracket 60. Upper guide shaft 64 thus extends across the tubepath 16 from a location on the nearside of the tube path to a locationon the other or remote side of the tube path.

Lower guide shaft 66 is positioned parallel to, below, and in the samevertical plane as upper guide shaft 64 with its lefthand or near end 66mounted in support bracket 58 and its righthand or other end secured insupport bracket 62. Lower guide shaft 66 is thus positioned totally onthe near or lefthand side of tube path 16.

Cross slide 68 includes a relatively long upper portion 68a and arelatively short lower portion 68b. Upper guide shaft 64 passes througha through-bore 68c in upper cross slide portion 68a and lower guideshaft 66 passes through a through-bore 68d in lower cross slide portion68b. A pair of bearings 72 and 74 at the opposite ends of through-bore68c facilitate the journalling of upper guide shaft 64 in through-bore68c and a pair of bearings 76 and 78 facilitate the journalling of lowerguide shaft 66 in through-bore 68d.

A roller cam follower 80 secured by a screw 82 to cross slide 68 guidesin the curvilinear cam track 26a of cam 26 to reciprocate cross slide 68back and forth on guide shafts 64 and 66 in response to relativevertical movement between upper platen 12 and lower platen 14. Upperguide shaft 64 is hollow and receives a lubricating fitting 84 tofacilitate the introduction of lubricant into the sliding interfacebetween through-bore 68c and upper cross slide portion 68a. Similarly,lower guide shaft 66 is hollow and receives a lubricating fitting 86.Nuts 88 and 90 on the respective left or near ends of shafts 64 and 66facilitate the mounting of the shafts in their respective brackets.

Notching blade assembly 70 includes a notching or scarfing blade 92,blade clamps 94 and 96, a blade holder 98, guide brackets 100 and 101,and a slide 102.

Blade 92 is clamped to the righthand or free end of blade holder 98 byscrews 104 which secure the blade to the free end of the blade holder insandwich fashion between clamps 94 and 96. Thus secured, notching blade92 lies in the plane of cut-off blade 52 and in alignment with slot 55in die jaws 36 and 38.

Brackets 100 and 101 are secured by screws respectively in a pair ofparallel vertical grooves 68e formed in the forward face of cross slide68. Brackets 100 and 101 are L-shaped in cross section and are mountedto the forward face of cross slide 68 in confronting relation to eachother so as to define a guide channel 106 for vertical sliding receiptof slide member 102. A vertical rib 98a on the rear face of blade holder98 passes through the confronting inturned edges of brackets 100 and 101for engagement with the front face of slide 102. Blade holder 98 issecured to slide 102 by suitable screws 108.

A first adjustment screw 110 is threadably engaged at its upper end in athreaded bore in blade holder 98 with its head 110a positioned on top ofand pressing against a foot portion 100a of bracket 100, and a secondadjusting screw 112 is positioned with its upper end threadably engaginga threaded bore in blade holder 98 and with its lower end passing freelythrough a foot portion 101a of bracket 101 to position its head portion112a on the underside of foot portion 101a. Screw 110 is adjusted by anAllen head wrench passed upwardly through a bore 100b in foot portion100a of bracket 100 and screw 112 is adjusted by an Allen head wrenchreceived directly in a suitable socket in head 112a. It will be seenthat selective adjustment of screws 110 and 112 selectively varies thevertical position of blade holder 98, and thereby blade 92, with respectto cross slide 68 and provides a firm, non-cocking mounting of the bladeon cross slide 68 irrespective of the position of vertical adjustment ofthe blade on the cross slide.

The described mounting arrangement for the notching or scarfing bladewill be seen to provide a firm positive support for the blade throughoutits reciprocal motion to accomplish the notching stroke. Specifically,the described arrangement with the upper guide shaft extendingcompleteley across the path of the tubing in cooperation with the lowerguide shaft positioned to one side of the tube path maximizes thejournalling support of the cross slide and thereby maximizes thestability of the notching blade during its reciprocal movement. Theprovision of a positive and precise movement of the noching blade isimportant to the successful operation of a double-cut apparatus of thetype disclosed since the synchronization between the notching blade andthe guillotine or severing blade is critical. Specifically, since thenotching blade and cut-off blade are moving in a common plane, and sincetime is of the essence in making a flying cut of the type involved inthe double-cut apparatus, as the notching blade is moving from right toleft across the upper periphery of the tube to make the notching cut theguillotine has already begun its downward movement to accomplish thesevering cut. In actuality, the lefthand lower bevelled edge 52a of theguillotine passes precariously close to the righthand bevelled edges 98band 92a of the blade holder and notching blade respectively so that anycocking or misalignment of the blade holder or notching blade couldresult in interference between the blade holder and notching blade andthe descending cutting edge of the guillotine with disastrous results.The described support mechanism for the notching blade allows thevarious movements of the notching blade and guillotine to be preciselytimed with the assurance that the exquisite clearances programmedbetween the guillotine and the notching blade will be maintained inactuality and over sustained periods of use of the apparatus.

Although a preferred embodiment of the invention has been illustratedand described in detail, it will be apparent that various changes may bemade in the disclosed embodiment without departing from the scope orspirit of the invention.

We claim:
 1. In a cut-off die apparatus for tubing of the double cuttype including means for moving the tubing along a generally horizontalfeed path, means for performing a notching cut by a notching blademounted for reciprocal movement horizontally across the tube path, andmeans for performing a vertical severing cut following the notching cut,the improvement wherein the mounting means for the notching bladecomprises:(a) an upper guide shaft positioned over said path andextending from a location on one side of said path to a location on theother side of said path; (b) a lower guide shaft positioned beneath andparallel to said upper guide shaft and totally on said one side of saidpath; (c) a cross slide mounted for reciprocal sliding movement on saidguide shafts; and (d) means mounting said notching blade on said crossslide for reciprocal movement therewith across said path.
 2. A cut-offdie set according to claim 1 wherein:(e) said cross slide includes (1)an upper portion defining a relatively long journal surface slidablyengaging said upper guide shaft, and (2) a lower portion defining arelatively short journal surface slidably engaging said lower guideshaft.
 3. A cut-off die set according to claim 2 wherein:(f) saidjournal surfaces are provided by through-bores extending respectivelythrough said upper and lower portions of said cross slide.
 4. A cut-offdie set according to claim 3 wherein said apparatus further includes:(g)a lower platen underlying said path; (h) a first support structureupstanding from said lower platen at said one side of said path andrigidly supporting one end of each of said guide shafts; (i) a secondsupport structure upstanding from said lower platen at said other sideof said path and rigidly supporting the other end of said upper guideshaft; and (j) a third support structure upstanding from said lowerplaten between said first support structure and said path and rigidlysupporting the other end of said lower guide shaft.
 5. A cut-off die setaccording to claim 4 wherein:(k) said apparatus further includes anupper platen assembly including(1) an upper platen overlying said path,and (2) a plurality of guide rods extending downwardly from said upperplaten and guiding said upper platen for reciprocal vertical movementrelative to said lower platen; (l) said means for performing a verticalsevering cut includes a severing blade extending downwardly from saidupper platen over said path; and (m) said second support structureincludes a tubular member upstanding from said lower platen andtelescopically receiving one of said guide rods.
 6. A cut-off die setaccording to claim 5 wherein said apparatus further includes:(h) a cammember extending downwardly from said upper plate; and (o) a camfollower secured to said cross slide and guiding on said cam member tohorizontally reciprocate said cross slide on said guide shafts inresponse to vertical reciprocal movement of said upper platen relativeto said lower platen.
 7. A cut-off die apparatus for successivelysevering sections of tubing from a continuous length of tubing movingalong a tube path, said apparatus comprising:(a) a lower platenpositioned below said path; (b) a pair of die jaws mounted on said lowerplaten and selectively movable on said platen into clamping relation tothe tubing; (c) an upper platen positioned above said path over saidlower platen and mounted for vertical reciprocal movement relative tosaid lower platen between a raised rest position and a lowered cuttingposition; (d) an elongated guide member carried by and immovably securedto said lower platen and extending horizontally from one side of saidpath to the other side of said path at a level between said loweredposition of said upper platen and said path, said guide member beingspaced from and unconnected to both of said die jaws and both of saiddie jaws being movable on said lower platen relative to said guidemember into clamping relation to the tubing; (e) a cross slide mountedfor reciprocal horizontal movement on said guide member; (f) a notchingblade mounted on said cross slide and operative to make a notching cutin the upper periphery of the tubing in response to the reciprocalmovement of said cross slide on said guide member; and (g) a guillotineextending downwardly from said upper platen in the plane of saidnotching blade and operative to sever a section of tubing from the tubein response to movement of said upper platen from its raised to itslowered position following said notching cut of said notching blade. 8.In a cut-off die apparatus for tubing of the double cut type includingmeans for moving the tubing along a feed path, a platen positioned atone side of the feed path, a pair of die jaws movably mounted on theplaten for selective movement into clamping relation to the tubing asthe tubing moves along the feed path, means for performing a notchingcut by a notching blade mounted for reciprocal movement across the tubefeed path, and means for performing a severing cut following thenotching cut, the improvement wherein the mounting means for thenotching blade comprises:(A) a first elongated guide shaft lying in aflat plane intersecting said feed path and immovably mounted on saidplaten in a position spaced from said die jaws on the side of said feedpath opposite said one side thereof with said die jaws positionedbetween said guide shaft and said platen; (B) a second elongated guideshaft immovably mounted on said platen and lying in said plane inparallel spaced relation to said first guide shaft; (C) a cross slidemounted for reciprocal sliding movement along said guide shafts; and (D)means mounting said notching blade on said cross slide for reciprocalmovement therewith across said path.
 9. A cut-off die apparatusaccording to claim 8 wherein:(E) said feed path is horizontal, saidfirst guide shaft comprises an upper guide shaft and said second guideshaft comprises a lower guide shaft; and (F) said cross slideincludes(1) an upper portion defining a journal surface slidablyengaging said upper guide shaft, and (2) a lower portion defining aseparate journal surface slidably engaging said lower guide shaft.
 10. Acut-off die set according to claim 9 wherein:(G) said journal surfacesare provided by through-bores extending respectively through said upperand lower portions of said cross slide.
 11. A cut-off die set accordingto claim 10 wherein said platen is a lower platen underlying said pathand wherein said apparatus further includes:(H) a first supportstructure upstanding from said lower platen at one lateral side of saidpath and rigidly supporting one end of said guide shafts; and (I) asecond support structure upstanding from said lower platen between saidfirst support structure and said path and rigidly supporting said otherend of at least said lower guide shaft.
 12. A cut-off die apparatus forsuccessively severing sections of tubing from a continuous length oftubing moving along a tube path, said apparatus comprising:(a) a lowerplaten positioned below said path; (b) an upper platen positioned abovesaid path over said lower platen and mounted for vertical reciprocalmovement relative to said lower platen between a raised rest positionand a lowered cutting position; (c) a relatively long upper guide shaftcarried by said lower platen and extending horizontally from one side ofsaid path to the other side of said path at a level between said loweredposition of said upper platen and said path; (d) a relatively shortlower guide shaft positioned below said upper guide shaft on said oneside of said path; (e) a cross slide mounted for reciprocal horizontalmovement on said guide shafts and including an upper portion defining arelatively long journal surface slidably engaging said upper guide shaftand a lower portion defining a relatively short journal surface slidablyengaging said lower guide shaft; (f) a notching blade mounted on saidcross slide and operative to make a notching cut in the upper peripheryof the tubing in response to the reciprocal movement of said cross slideon said guide shafts; and (g) a guillotine extending downwardly fromsaid upper platen in the plane of said notching blade and operative tosever a section of tubing from the tube in response to movement of saidupper platen from its raised to its lowered position following saidnotching cut of said notching blade.
 13. A cut-off die set according toclaim 12 wherein said apparatus further includes:(h) a cam memberextending downwardly from said upper platen; and (i) a cam followersecured to said cross slide and guiding on said cam member tohorizontally reciprocate said cross slide on said guide shafts inresponse to vertical reciprocal movement on said upper platen relativeto said lower platen.